The present application claims priority to Japanese Application No. P11-084619 filed Mar. 26, 1999 which application is incorporated herein by reference to the extent permitted by law.
1. Field of the Invention
This invention relates to an air cell having an air electrode for exploiting oxygen in air for a positive electrode reaction.
2. Description of Prior Art
Among the batteries, there is a so-called air cell which is a primary battery having an air electrode exploiting oxygen in air for a positive electrode reaction. This air cell, employing oxygen as a positive electrode active material, has a feature that there is no necessity of charging particles of e.g., manganese dioxide such that the air electrode can be thin in thickness. In the air cell, in which the air electrode as the positive electrode can be reduced in thickness, the capacity of the negative electrode can be increased correspondingly and hence the air cell is a high energy density battery having an extremely large discharge capacity per unit volume.
In the air cell, an air electrode having a porous electrode material and a gelated negative electrode mixture composed of the negative electrode active material, and an electrolyte solution, are accommodated, via a separator, in a battery can having at least air openings. In the air cell, outside air flows into the battery can bored in the wall section of the can, with the oxygen contained in the influx air then being adsorbed on the porous electrode material to undergo a positive electrode reaction.
In such air cell, both ends of the tubular air electrode were sealed to prevent the leakage of the gelated negative electrode mixture charged into the interior of the air electrode. Specifically, one of the opening ends is sealed by caulking a metallic ring constituting a sealant along with a resin gasket molded as one with the metallic ring. The other end of the air electrode is sealed by caulking metallic ring or a metallic cup.
In the above-described air cell, it is crucial to seal both ends of the air electrode reliably to improve solution leakage characteristics. However, the above-described air cell suffers from a problem that the solution leakage preventative performance at both ends of the battery cannot be said to be optimum.
It is therefore an object of the present invention to provide an air cell in which at least one end of a tubular air electrode is sealed reliably to improve the solution leakage preventative characteristics.
In one aspect, the present invention provides an air cell including an air electrode in the form of a hollow tube, a holding member abutted against at least one end of the air electrode along the circumference on the inner peripheral surface of the air electrode, a ring-like gasket arranged facing the holding member with the air electrode in-between, with the ring-like gasket abutting along the circumference against the outer peripheral surface of air electrode. The air cell also includes a sealant member clinching the ring-like gasket and the air electrode along with the holding member for closing the end of air electrode. The ring-like gasket seals the sealant member and the air electrode to each other by being clinched by the sealant member and the holding member.
In the air cell according to the present invention, the ring-like gasket is arranged between the sealant member provided on the outer peripheral side of the air electrode and the air electrode. Thus, with the present air cell, the interior of the air electrode, in the form of a hollow tube, is positively sealed by the sealant member and the ring-like gasket.
With the air cell according to the present invention, in which the ring-like gasket and the air electrode are clinched by the sealant member and the holding member, both ends of the air electrode can be positively sealed to improve leakage-proofing characteristics.
In another aspect, the present invention provides an air cell including an air electrode in the form of a hollow tube, an outer peripheral can in the form of a cylinder larger in diameter than the air electrode for accommodating the air electrode therein, and a groove formed on drawing. The groove radially compresses at least a portion of the outer peripheral surface of at least one end of the outer peripheral can. The air cell also includes a ring-like gasket arranged between air electrode and the outer peripheral can, with the ring-like gasket abutting along the circumference against the inner peripheral surface of one end of outer peripheral can. The air cell also includes a holding member arranged facing the ring-like gasket with the air electrode in-between, with the holding member abutting along the circumference against the inner peripheral surface of air electrode. The ring-like gasket seals the outer peripheral can and the air electrode relative to each other by being clinched by the groove formed on drawing in the outer peripheral can and holding member. In this air cell, according to the present invention, the ring-like gasket 11 is arranged between the air electrode and the outer peripheral can. In this air cell, a groove is formed on drawing in at least a portion of the outer peripheral can for thrusting the ring-like gasket. Thus, with the present air cell, the interior of the air electrode, formed as a hollow tube, can be positively sealed by the outer peripheral can and the ring-like gasket.
With the air cell according to the present invention, in which the ring-like gasket and the air electrode are clinched by the groove formed on drawing in the outer peripheral can and by the holding member, both ends of the air electrode can be positively sealed to improve leakage-proofing characteristics.